热应激对两种高密度饲养模式下笼养蛋鸡血液生化指标的影响

Impact of Heat Stress on Plasma Index of High-density Layers Keeping in Two Cascading Cages

以抗氧化酶活性、血脂、肿瘤坏死因子α、皮质醇以及热应激蛋白70为比较指标,研究两种层叠笼(4层层叠笼和8层层叠笼)饲养模式下,热应激对鸡舍末端蛋鸡血浆生理生化指标的影响。结果表明:相较于适温环境,热应激导致两种层叠笼饲养模式下蛋鸡抗氧化酶活性显著降低(P<0.05),热应激蛋白表达显著增加(P<0.05)。且4层层叠笼鸡群的血浆热应激相关蛋白水平显著低于8层层叠笼鸡群;相较于适温环境,热应激未导致4层层叠笼鸡群的血浆血脂水平发生显著变化(P>0.05),而8层层叠笼鸡群的血浆血脂水平显著下降(P<0.05)。此外,夏季4层层叠笼鸡群的生产性能要好于8层层叠笼鸡群,表明层叠笼层数越多夏季鸡群受到的应激越严重。建议在夏季高密度层叠式笼养鸡舍要降低饲养密度,新建鸡舍应适当降低层叠笼层数和鸡舍长度,以降低热应激带来的损失。

To explore the effect of heat stress on plasma parameter in high-density layers keeping in two cascading cage systems（4-high and 8-high manuer-belt cage system）, the activities of plasma anti-oxidative enzymes, plasma lipid content, as well as the content of plasma heating stress related proteins were measured. The results showed that heating stress significantly decreased the activities of antioxidant enzymes（P〈0.05）, and increased the content of heating stress related proteins in the laying hens keeping in both systems（P〈0.05）. In addition, the content of heating stress related proteins in hens of 4-high manuer-belt cage system was lower than that kept in 8-high manuer-belt cage system（P〈0.05）. No significant changes of plasma lipid contents were observed in hens kept in 4-high manuer-belt cage system under high temperature condition, while significant decrease was observed in hens in 8-high manuer-belt cage system（P〈0.05）. The results indicated that the more cascading cages the cage system had, the more stress induced by high temperature hens got in summer. To decreased the economic lose caused by heating stress, we suggested that the density of layers should be reduced in summer, and the less cascading number and length of henhouse showed be selected for new laying house.